Metal joist



May 5, 1964 A. DAVIS, JR., ETAL METAL JoIsT Filed May 18, 1959 United States Patent Office 3,131,791 Patented May 5, 1964 3,131,791 METAL J OIST Augustine Davis, Jr., and .lames A. Nichols, Washington, D.C., assignors to Davisbilt Steel .loist Inc., Washington, D.C., a corporation of Delaware Filed May 18, 1959, Ser. No. 813,711 2 Claims. (Cl. 1559-37) (Ibis invention relates to improvements in a nailable metal joist for building construction.

As has been noted in our prior United States Patent No. 2,578,465, for Metal Joist, which issued December 11, 1951, and our prior United States Patent No. 2,950,789, for Metal Structural Units, the advantages of metal over wooden joists, including strength, availability, freedom lfrom shrinkage and from warpage, reproofness, maintenance and holding power in the retention of floor fastenings, has been known for some time.

Nevertheless, the building construction industry has resisted universal substitution of metal joists for their wooden counterparts due to the comparatively high expense involved in the manufacture of such metal joists as have been proposed heretofore.

It is, therefore, an object of this invention to provide a nailable metal joist which is of relatively simple improved construction, and which can be mass produced with regard to a favorable cost picture.

It is another object of this invention to provide a nailable metal joist which is of light weight and which is capable of supporting heavy' loads in conformance with the structural requirements of the various building codes.

It is a further object of this invention to provide a nailable metal joist comprising a web of any suitable construction or conguration and ya top chord member of nailable sheet steel stock of hollow construction and with walls of a gauge adapted to be penetrated by a nail or drive screw without special tools, techniques, or undue expenditure of energy.

Other objects and features of novely will be apparent from the following speciication, when read in connection with the accompanying drawings, in which certain embodiments of the invention `are illustrated by way of example.

In the drawings:

FIGURE 1 is a fragmentary view in perspective of a metal joist embodying the principles of the invention and having a section of wooden flooring nailed thereto.

FIGURE Z is Ian enlarged view in transverse vertical section through the metal joist and wooden ooring of FIGURE l and showing to better advantage the novel top chord member of the joist.

FIGURE 3 is la similar sectional view in side elevation of a joist representing a second embodiment of the invention.

FIGURE 4 is a similar sectional view in side elevation of -a joist representing a third embodiment of the invention.

FIGURE 5 is a similar sectional view in side elevation of la joist representing a fourth embodiment of the invention.

FIGURE 6 is a side elevation along the line 6--6 of FIGURE l. and showing to better advantage the web of the joist.

Referring now to the drawings, in FIGURES 1, 2 and 6 there is illustrated one preferred embodiment of the invention in which the novel metal joist is indicated generally by the reference numr 10. This metal joist comprises a web 11, which may be of any' suitable material, and a top lchord member 12, 13 including a pair of opposed, elongated, box-like, supporting elements shown at 12 and 13. Each of these supporting elements may be made up of rolled sheet steel stock, substantially rectangular in cross-section. These supporting elements 12 and 13 -are so constructed as to have opposite, spacedapart, parallel boundary walls 14 and 15 of nail-penetrable sheet metal, which is of equivalent strength and penetrability to sheet steel of l-gauge thickness; and the interior 16 of the supporting members 12 and 13 is hollow and unlled. In this regard, it is not necessary for the supporting elements of the chord to enclose a structure of wood or other similar nail receiving and retaining Iiller. The novel construction of the rectangular, box-like, supporting elements results in a structurally rigid yand selfsustaining top chord member. Although the box-like supporting ele-ments 12, 13 may be formed by joining two rolled steel channel sections, it is the preferred ernbcdiment of this invention to provide a rectangular boxlike supporting element formed from -a single piece of sheet steel stock that has been rolled back upon itself so that the ends meet along the seam 16a, as shown in FIGURE 2. The supporting elements 12 and 13 are atcached to the web 11 by means of suitable welds 17, so that the top y'boundary walls 14 are `substantially ush with the top of the webV section. Additional Welds 17a may be added along the seam 16a and intersticed between the welds 17, so as to add strength to the box-like supporting element, as shown in FIGURE 6.

The collateral structural member 1S is secured to the top chord by means of driven frictional fastening elements 19, which may be any suitable hardened helical drive nails or drive screws but are preferably of No. 6 size, and which pass through the :structural flooring 13 land also successively through the spaced-apart boundary walls 14 and 15 and the hollow interior 16 of the supporting elements 12 and 13. It is thus possible to nail the collateral structure 18 to the chord anywhere along the hollow supporting elements of the chord without having to hit any prearranged nail receptacle within the chord. The nail 19, once driven entirely through the hollow supporting elements of the chord, is retained securely in place by its frictional contact with the distorted margins of the openings 14a and 15a formed in the spaced-apart boundary walls 14 and 15, combined with the locking effect of the slight deflection of at least one of the parallel walls 14 and 15, preferably the top wall 14, due to the inherent slight unhindered resilience thereof under the driving force of the fastening element. The collateral lstructural member 18 may comprise a part of the wooden flooring supported by said joist or may be a metal bridging member, which is of no thicker gauge than that of the hollow joist chord and, therefore, readily nailable to the chord. iI'he joist includes a suitable bottom chord 50 which may be welded to the web 11, as shown in FIGURE 6.

A second embodiment of the nove-l metal joist comprising my invention is shown in FIGURE 3, in which the metal joist is indicated generally by reference number 20, and comprises a web 21 and 'a top chord member 22, 223 joined along one edge thereof. The :top chord includes an elongated harige-like supporting element, such as the angle shown at |22,1which is substantially L-shaped in cross-section, and an opposed, elongated, box-like, supporting element 23, which is substantially rectangular in cross-sectional configuration. The supporting element 23 is so constructed as to have opposite, spaced-apart, parallel boundary -walls 24 and 25 of nail-penetrable sheet metal which enclose a hollow, unfilled interior Z6. The supporting elements 23r is of nail-penetrable metal, which may be of sheet metal of 4the equivalent strength and penetrability to sheet steel of l-gauge thickness. The chord is structually' rigid and self-sustaining, and is Welded to the web 21 by sui-table welds 27. A collateral structural member 28 is disposed adjacent to and supported by the chord 22, 23 and is fastened thereto by driven frictional fastening elements 29, which pass through the collateral member 28 and also successively through the spaced-apart boundary Walls 24 and 25 and the hollow, unfilled interior 26 of the supporting element 23. y

A Ithird embodiment of lthe invention is Vshown in FIGURE 4, in lwhich the metal joist, indicated generally at 30, comprises a web 31 and a top chordrmember 32, 33 extending along one edge thereof. The top chord includes a pair of opposed, elongated flange-like supporting elements substantially L-shaped in cross-section, such as the angle shown `at 32 and the opposed inverted angle shown at 32a, and an elongated, box-like, supporting element 33, which is substantially square in cross-sectional. configuration. The supporting element '33 is mounted on the Web31 opposite the angle 32 and above langle 32a, and is so constructed as -to have opposite, spaced-apart, parallel boundary walls 34 :and 35 of nail-penetrable sheet metal, which may be of the equivalent strength and penetrability of sheet metal of 16 or 18-gauge thickness. The chord is structurally rigid and self-sustaining and is Welded to the web 31 by suitable welds 37. A collateral structural member 38 is disposed adjacent to and supported by the chord 32, 33 and is fastened thereto by `driven frictional fastening elements 39, which pass through the collateral member 38 and also successively through the spaced-apart boundary Walls 34 and 35 and the hollow, until-led interior 36 of the supponting element 33.

A .fourth embodiment of the invention is shown in FIGURE 5, in which the metal joist, indicated generally at 40, comprises a web 41 and a top chord member 42, 43.extending along one edge thereof. The top ohord inclludes a pair of opposed, elongated flange-like supporting elements, substantially L-shaped in cross-section, such as the angle shown lat 42 and the opposed inverted angle shown at 42a, and an lelongated box-like supporting element 43, -whioh is substantially square in cross-sectional configuration. The supponting element 43 is mounted on the upper extension of the angle 42a and on the opposite side of the web 441 tothe angle 42, and is so constructed as to have opposite, spaced-apart, parallel boundary Walls 44 and 45 of nail-penetrable sheet metal, which may be of the equivalent strength and penetrability of sheet steel of 18-gauge thickness. The chord is structurally rigid and self-sustaining ,and is Welded to the web 41 by suitable welds 47. A collateral structural member 48 is disposed adjacent lto and supported by the chord 42, 43 l It will be apparent from the foregoing description and explanation that rthe invention provides a nailable metal joist having numerous advantages over joists of this type previously available.

While the arrangement of the invention described herein is at present considered lto be preferred, it is understood that Ivariations and modifications may be made therein, andy it is intended to cover in the appended claims all such variations rand modifications as fall Iwithin the true spirit and scope of fthe invention.

What is claimed is:

1. A metal joist lfor supporting a collateral member and receiving driven frictional fastening means passing through the collateral member and securing it to the joist, comprising; web means, a chord joined to said web means along one edgethereof, said chord including a pair of longitudinally extending, elongated supporting elements bracketing said web means, one of said supporting elements being hollow and generally rectangular in cross-sectional configuration, said one element having opposite'ly disposed parallel Walls of nail penetrable sheet metal, said parallel nail penetrable Walls adapted to be penetrated b-y the driven frotional fastening means, the openings formed in the sheet metal by the fastening means having distorted margins which frictionally retain the fastening means and consequently the collateral member securely in place on the joist, the other of saidY supporting elements comprising a generally L-shaped frange formed independently of and secured to 'said web means, one of the legs of said L-shaped flange adapted to support the collateral member in flush relationship.

2. The mertal joist of claim l further characterized by and including a second longitudinally extending, elongated L-shaped ange secured to said web means on the opposite side of said web means to said other supporting element, said hollow supporting element being mounted on one leg of said second L-sh-aped ilange.

References Cited in the iile of this patent UNITED STATES PATENTS I1,351,615 Brown et al Arug. 31, 1920 I1,523,106 Dornier Ian. 13, 1925 2,246,215 Nagin June 17, 1941 2,391,250 Legowik Dec. 18, 1945 2,578,465 Davis Dec. ll, 1951 2,605,867 Goodwin Aug. 5, 1952 FOREIGN PATENTS 131,019 Great Britain Aug. 21, 1919 

1. A METAL JOIST FOR SUPPORTING A COLLATERAL MEMBER AND RECEIVING DRIVEN FRICTIONAL FASTENING MEANS PASSING THROUGH THE COLLATERAL MEMBER AND SECURING IT TO THE JOIST, COMPRISING; WEB MEANS, A CHORD JOINED TO SAID WEB MEANS ALONG ONE EDGE THEREOF, SAID CHORD INCLUDING A PAIR OF LONGITUDINALLY EXTENDING, ELONGATED SUPPORTING ELEMENTS BRACKETING SAID WEB MEANS, ONE OF SAID SUPPORTING ELEMENTS BEING HOLLOW AND GENERALLY RECTANGULAR IN CROSS-SECTIONAL CONFIGURATION, SAID ONE ELEMENT HAVING OPPOSITELY DISPOSED PARALLEL WALLS OF NAIL PENETRABLE SHEET METAL, SAID PARALLEL NAIL PENETRABLE WALLS ADAPTED TO BE PENETRATED BY THE DRIVEN FRICTIONAL FASTENING MEANS, THE OPENINGS FORMED IN THE SHEET METAL BY THE FASTENING MEANS HAVING DISTORTED MARGINS WHICH FRICTIONALLY RETAIN THE FASTENING MEANS AND CONSEQUENTLY THE COLLATERAL MEMBER SECURELY IN PLACE ON THE JOIST, THE OTHER OF SAID SUPPORTING ELEMENTS COMPRISING A GENERALLY L-SHAPED FLANGE FORMED INDEPENDENTLY OF AND SECURED TO SAID WEB MEANS, ONE OF THE LEGS OF SAID L-SHAPED FLANGE ADAPTED TO SUPPORT THE COLLATERAL MEMBER IN FLUSH RELATIONSHIP. 